JP7399279B2 - Integrated, modular motors or generators and small, modular pumps or turbines with coaxial fluid flow - Google Patents

Description

RELATED APPLICATIONS This application claims the benefit of U.S. Application No. 16/668,665, filed October 30, 2019, which is incorporated by reference in its entirety for all purposes.

TECHNICAL FIELD This invention relates to pumps and turbines, and more particularly to integrated, sealless pumps and turbines.

Because turbopumps and turboturbines are often very similar in physical design, the difference between a pump and a turbine may be primarily a matter of usage rather than construction. Accordingly, inventive features and prior art features discussed herein with respect to turbines or pumps should be understood to refer equally to both, unless the text clearly indicates otherwise.

In traditional turbo pump designs, fluid flow and pressure are generated by rotors, also called "rotor vanes," that rotate within a stationary pump casing. The torque required to drive the rotor is provided by an external motor and transmitted to the rotor via a rotating shaft that rotates within the pump housing. Similarly, in conventional turbine designs, fluid flow and pressure are applied to the rotor. The rotor, also called a "runner" in the case of a turbine, rotates the rotor within a stationary turbine casing, and the rotation and torque generated by the rotor is transmitted to an external generator via a rotating shaft.

One of the difficulties with these approaches is that they require the use of dynamic seals to maintain pressure boundaries where the rotating shaft passes through the casing of a stationary pump or turbine. These seals are susceptible to leaks and other failure modes. Also, a rigid base plate is required to mount the pump and motor or turbine and generator so that they are in line with each other to avoid vibration problems. Even with a rigid base plate, nozzle loads on the pump or turbine can cause alignment problems between the motor or generator and the mechanical seal.

These difficulties are avoided in designs that do not include shaft seals. For example, magnetic coupling drives do not require dynamic seals on the pump or turbine shaft. This is because the motor or generator is magnetically coupled through the pump housing to an internal shaft supported on product lubricated bearings located within the housing. However, these designs still require careful alignment of the motor or generator and the rotor housing in order to couple the motor or generator to the rotor shaft as efficiently as possible. Additionally, the components used for magnetic coupling add complexity and cost to the design.

Another approach to completely avoid dynamic shaft seals is to use a monolithic design, where the motor or generator is contained within the same housing as the rotor and no shaft seal is required. Some of these integrated so-called "sealless motor" or "sealless generator" approaches use a radial field motor or generator design, whereby the magnets are connected to the outside diameter of the rotor. Mounted at or near the rotor, the rotor is sealed within a thin-walled "can" and an electromagnetic stator outside the sealed can surrounds the rotor. However, radial field designs necessarily require significantly longer rotor housing diameters and lengths. Another approach to integral pump design is to implement an axial field motor or generator design, whereby a disk or "pancake" permanent magnet, brushless DC motor or generator is mounted on the rotor housing. This allows for high power densities and the smallest and lightest possible single-stage pump or turbine unit.

However, cooling the motor or generator coils of an integrated sealless motor pump or sealless generator turbine can be difficult. Usually within the housing to shunt a portion of the working fluid into a submerged bearing groove and/or to another suitable path for extracting the heat generated from the motor or generator coils. Special flow channels must be provided. The shunted working fluid is heated by convection from the stator walls, carrying heat away from the stator and being discharged with the non-shunted working fluid.

Unfortunately, as the shunted fluid passes through passages adjacent to the stator walls, hollow rotating shafts, shaft bearings, and/or other suitable channels, fluid heating and/or transitions from discharge pressure to suction pressure occur. The combination of pressure drop caused by this can lead to a phase change. Exposure of the fluid to the gas phase can result in motor/generator overheating and/or bearing failure. Furthermore, the requirement to divert a certain portion of the pump power or turbine input to cooling flow necessarily reduces the efficiency of the pump or turbine.

Another disadvantage of pumps and turbines prior to the present invention that included mechanically integrated motors or generators was that each pump or turbine design necessarily required a corresponding integrated motor or generator design. This is the point. Therefore, when you introduce a new pump or turbine design, you also introduce a new motor or generator design, even though the torque and electrical requirements of the new motor or generator remain unchanged compared to the existing design. Must. Additionally, if multiple such pumps or turbines need to be manufactured and/or supported simultaneously, separate manufacturing and/or inventory must be maintained for separate motor or generator designs. be.

In addition to the problems described above, another common problem found in both integrated and non-integrated pump and turbine designs is the need to modify existing pumps or turbines to meet new application requirements. How to increase the capacity of a design, typically by redesigning the physical shape and size of the rotor, making the rotor run faster, and/or adding another rotor. is necessary.

The total head produced by the pump is determined by the diameter of the rotor and its rotational speed, while the flow rate for a particular rotor diameter and speed is determined by the width of the rotor. For certain rotor designs, the maximum speed of the rotor is limited by the amount of torque that the motor can generate. The rotational speed is also limited both by the frequency limit of the inverter used to drive the motor and by the NPSH (net suction head) available at the inlet of the rotor.

Similarly, in the case of a generator turbine, the generator "loads" the turbine rotor according to the electromagnetic coupling between the rotating magnets and the generator coils, under control of the inverter or other control electronics associated with the generator. multiply. The maximum output of the generator thereby depends on the maximum torque that the rotor can deliver to the generator, which for a given fluid flow depends on the diameter and width of the rotor.

Therefore, one approach to increasing the output of a pump or turbine is to increase the size of the rotor and the capacity of the motor or generator. However, the additional size and bulk resulting from this approach can be problematic.

The size and bulk of the rotor casing and other components of the pump or turbine may be reduced by using smaller diameter rotors and operating at higher speeds when higher fluid pressures or generator outputs are required. I can do it. However, this approach is not valid for sealless motor or generator designs because the rotor is also a component of the motor or generator. Particularly in axial sealless designs, smaller diameter rotors have less disk area available for mounting permanent or induction magnets, thereby limiting the torque that can be generated by a motor or the power that can be produced by a generator. be done. Another limitation is the relative unavailability of sealless motor designs (magnetic rotors and magnetic stators) that can deliver at a variety of pressures and flow rates and sealless generator designs that operate efficiently at a variety of pressures and flow rates. It is.

Therefore, in the case of axial motor sealless pumps or turbines, the power of the pump head or turbine provided by the rotor can only be increased by increasing the diameter of the rotor. However, this approach requires the use of large, thick rotor casings and other structural components to accommodate large components and high fluid pressures, thereby increasing the bulk of the equipment.

Increasing power by increasing the number of rotors can also be problematic for pump or turbine design. In a non-integral multi-stage pump or turbine, a single large motor provides torque to multiple rotors through a common shaft, or receives torque from multiple rotors through a single large generator common shaft. This approach typically requires a large, bulky motor or generator, and as the number of rotor stages increases, the shaft diameter and length must increase, thereby balancing the torque and weight of all rotors. can adapt to different things.

Whether configured in a horizontal or vertical configuration, these long shafts with multiple rotor stages require large bearings, increasing the likelihood of bearing failure. Additionally, the long shafts of multi-stage pumps can cause various rotational dynamics problems related to shaft deflection and critical speeds. For these and other reasons, each multi-stage pump design is applicable only to a specified maximum number of stages and cannot be easily scaled to accommodate requirements for different number of stages. Instead, scaling an existing design typically requires a new pump or turbine design.

Additionally, the elongated shaft, multi-stage approach requires all rotors to rotate at the same speed, which can limit design efficiency and/or NPSH (net suction head) performance. Also, failure of any one stage of a multi-stage pump immediately causes complete failure of the entire pump or turbine.

Of course, one alternative to designing and implementing multi-stage integral or non-integral pumps or turbines is simply to interconnect multiple single stage pumps or turbines in series and/or parallel. In the case of pumps, the output of each pump in series becomes the input of the next pump, which further increases the pressure, while the outputs of pumps configured in parallel add together to increase the output flow rate. In the case of a turbine, fluid flows through the rotor either in series or in parallel, and the electrical output of the turbine generators is summed in series and/or in parallel to increase the total output of voltage and/or current.

However, this approach of combining multiple pumps or turbines into a multi-stage device requires the use of bulky and complex fluidic interconnects or manifolds, resulting in excessive space consumption. Also, as the number of pumps or turbines increases, the reliability of the equipment decreases due to the increased number of hoses and/or other fluid connections and the associated increased opportunities for leaks and/or other failure modes.

It has been suggested that sealless disc motor pumps may include two or more motors within a common housing. However, the fluid interconnection requirements and motor/generator cooling requirements of sealless disc motor designs tend to limit this approach to only two stages at most.

For example, referring to FIG. 1, one proposed approach includes two centrifugal pump stages within a single sealless motor design 100, such that each stage is driven by its own motor 102 and two The stages are arranged back-to-back so that the two motors 102 can be contained within a common central space within the casing 112 and cooled by a common process flow path 104. In the example shown in FIG. 1, the two rotors 106 are oriented in opposite directions and each rotor includes a permanent magnet 110 mounted on the back.

In some versions of this approach, motor 102 is controlled by a separate variable frequency drive (“VFD”) 114 and each rotor 106 rotates about a separate fixed shaft 108. In other versions, the motors share a common controller and/or shaft. By placing the two motors 102 in the same volume, the cooling path 104 in this approach is only slightly more complex than that of a single-stage integrated motor design, and flow is diverted to the cooling path. Efficiency losses due to this are minimized. However, this technique is limited by its nature to only two stages, and there is no clear method to extend the design beyond the two-stage limit.

What is needed, therefore, is an integrated "sealless" pump or sealless turbine design that is compact and modular, allowing the bulk of the space between three or more pump or turbine modules, and preferably up to an arbitrarily large number. Can be combined in series without fluidic interconnections. It is further preferred in embodiments that the process fluid for cooling the motor or generator in each module has little or no deflection from the main flow path, that the rotors of the modules rotate independently, and/or Or the module's motor/generator can be controlled separately. It is also desirable that motors or generators that are integrated with pump or turbine modules should themselves be modular, so that the same motor or generator design can be used with different pump or turbine designs. It becomes possible to incorporate it into

The present invention is a "sealless" motor pump or sealless generator turbine constructed as a very compact module with a flow "concentric" design. The disclosed modular design allows for the installation of three or more pump or turbine modules, preferably up to any large number, with each module's rotor rotating separately on its own shaft or other support. can be combined in series without bulky fluidic interconnections. In embodiments, the process fluid for cooling the motor or generator within each module has little or no deflection from the main flow path. In various embodiments, the rotor of the module motor or generator is separately controllable. And in embodiments, the motor or generator integrated with the pump or turbine module is itself modular, allowing the same motor or generator design to be incorporated into different pump or turbine designs.

According to the invention, the coil housing of the motor or generator, i.e. the stator housing, is concentrically surrounded by the outer housing of the module, i.e. the module housing, thereby enclosing the motor or generator coils between them and the motor. Alternatively, an annular space centered around the main shaft of the generator is created. The working fluid enters the module axially through a proximal inlet located substantially along the major axis, and from the module through a distal outlet also located substantially along the major axis. ejected in the direction. Within the module, the working fluid is routed through a plurality of substantially identical flow paths symmetrically arranged around the stator housing, or through a single annular flow path surrounding the stator housing, to the motor or generator. It flows symmetrically through the stator housing surrounding the coil. The symmetrical distribution of the flow channels in the area surrounding the motor or generator coils results in a compact design in which the diameter of the module housing is only moderately larger than the stator housing of the motor or generator.

In various embodiments suitable for use with relatively low temperature working fluids, the plurality of channels or the single annular channel is in direct thermal contact with the housing of the motor or generator coil; Thereby directly cooling the motor or generator coils. In some of these embodiments, more than 80% of the working fluid is in thermal contact with the motor or generator coil housing, and at least 20% of the motor or generator coil housing is in thermal contact with the working fluid. In various embodiments, more than 90% of the working fluid is in thermal contact with the motor or generator coil housing, and at least 50% of the motor or generator coil housing surface is in thermal contact with the working fluid.

In multi-stage embodiments suitable for use with high temperature working fluids, insulation is provided between each of the plurality of substantially identical flow paths and the housing of the motor or generator coil. In some of these embodiments, cooling fluid flows in an annular space around the motor or generator coil housing such that the cooling fluid is in direct contact with the motor or generator coil housing, thereby Cools the coil and protects it from residual heating by the hot working fluid.

In other embodiments where the hot working fluid flows through a single annular channel, insulation is provided between the annular channel and the motor or generator coil housing, and in some of these embodiments, A separate cooling fluid flows through a cooling ring or channel provided below the insulation.

In embodiments, the concentric design of the present invention provides an extremely compact design that can be used in series with one or more identical modules to form a multi-stage pump or turbine, each stage containing both a rotor and an associated motor or generator. It is realized as a module. This modular design allows modules to be combined in any number of stages without adding additional complexity or complexity to the design, operation, and maintenance of the device. In particular, each module's rotor is supported by a dedicated shaft or other support, so even if the number of stages is large, shaft size, shaft deflection, rotational dynamics, bearing loads, motor alignment, or stage There are no problems with their alignment.

In some embodiments, the rotor of each module is fixed to a rotating shaft. In other embodiments, the shaft of each module is fixed and the rotor rotates about the shaft, for example on bearings. For example, the shaft of each module can be inserted through the hub of the rotor and screwed into the module housing, facilitating easy assembly and maintenance without special tools.

Certain embodiments include modules in which the rotor and stator configurations are reversed, such that both the rotor and stator can rotate in opposite directions independently of each other. Some embodiments include individually rotating stators and/or diffusers. In some of these embodiments, the diffuser is implemented in a manner similar to the disclosure of U.S. patent application Ser. No. 15/101,460, which is incorporated herein by reference in its entirety for all purposes. .

In yet other embodiments, the disclosed module does not include a shaft. Instead, the wear ring gap in front of the rotor acts as the primary radial and axial bearing. This either transfers torque directly from the motor's electromagnetic stator coil to the rotor, or transfers electromagnetic energy from the rotor to the generator, without using a rotating shaft.

In some embodiments, the disclosed pump or turbine module includes a radial motor or generator design whereby a plurality of permanent magnets are mounted at or near the circumference of a rotor, and the rotor is connected to an electromagnetic stator. surrounded by. In other embodiments, the disclosed module includes an axial "disk" or "pancake" shaped motor or generator, whereby a plurality of permanent magnets are mounted behind the rotor and as the rotor rotates. , passing close to the electromagnetic coils of the axially adjacent stators. Some embodiments that include a permanent magnet motor or generator further include a variable speed drive that allows the synchronous operating speed of the module to increase above 3600 rpm.

Other embodiments include induction motors or induction generators that utilize non-permanent magnets, such as "squirrel-cage" rotor coils, in which current is induced by stator electromagnets during pump or turbine operation.

In embodiments, the motor or generator coils are sealed from the working fluid using a static sealing method, thereby eliminating the need for dynamic mechanical seals that would otherwise result from Avoid alignment, leakage, and/or maintenance problems.

Various embodiments with centrifugal designs include radial flow rotors. Some of these embodiments include rotors with specific speeds up to about 2000 US units, 4000 US units, or even 5000 US units. Other embodiments include stages that are radial flux motor or generator designs and higher specific speed mixed flow rotor designs.

In embodiments, the rotor is arranged axially and radially with product lubricated bearings in each modular stage, such that the bearings in each stage are designed to handle loads only from that stage. can do. This approach completely eliminates the risk of overloading the bearings due to the combined stage loads in a multi-stage arrangement, and results in a more compact design since there is no need to use oversized bearings. Using the working fluid as a bearing lubricant in embodiments also eliminates the need for an external oil lubrication system, greatly simplifying the overall pump design. Embodiments use a combination of radial and unidirectional thrust bearings instead of separate axial and radial bearings.

In various embodiments, the motors or generators of the multi-stage device are separately controllable. Embodiments include multiple variable frequency drives (VFDs), and in some of these embodiments, each stage motor or generator is independently controlled by a dedicated VFD. One important advantage of some of these embodiments is that the first stage runs slower than the rest of the equipment to accommodate low net suction head ("NPSH") and off-peak conditions. It is possible. In some applications, varying the speed of only the last stage can be a useful technique to precisely control output pressure and/or flow.

Providing individual VFD drives for each stage can also serve as fail-safe redundancy, so that if one stage fails, the rest will continue to operate and the device will continue to function. Continuing function after a pump or turbine stage fails may have less head and flow, or the speed of the remaining stages may be increased to compensate for the loss of head and flow of the failed stage. This approach creates a failure scenario in which the pump or turbine continues to operate at potentially reduced head and flow until the operator has time to safely shut down the system after noticing a stage failure. In contrast, when one stage of a conventional pump or turbine fails, the entire device fails, resulting in a complete loss of performance and a sudden and uncontrollable shutdown of the system. The use of sensorless motors with appropriate VFDs also reduces instrumentation requirements for each stage of various embodiments.

In various embodiments, the motors or generators included in each module are modular in design, such that a particular motor or generator design can be incorporated into multiple different pump or turbine designs. In particular, multiple permanent magnets or other magnetic devices contained in a motor or generator can be assembled into removable, modular magnet structures that can be axially and rotationally constrained to cooperate with the rotor of a pump or turbine. include. The axial and rotational restraint of the magnet structure is possible by any means known in the prior art that allows the magnet structure to be both axially and rotationally restrained relative to the rotor. Embodiments include a snap ring that axially constrains the magnet structure and one or more pins that rotationally secure the magnet structure to the rotor. Other embodiments include mounting components that thread the magnet structure onto the rotor, or screw or bolt mounting components, thereby constraining the magnet structure both axially and rotationally. Some of these embodiments include a connection between the motor or generator housing and the pump or turbine housing such that there is a passageway for electrical leads and/or control lines to extend between the stator and the external environment of the pump or turbine. It further has an electrical port capable of forming a sealed conduit therebetween.

In embodiments, the magnet structure and/or stator portion of the motor or turbine containing the stator coils are modular and fully sealed so that they mechanically attach to the housing of the pump or turbine in close proximity to each other. There is only a need. In various embodiments, the sealed modular magnet structures and/or sealed modular stator assemblies of the present invention can be realized in different combinations, with each new pump or turbine module being designed There is no need to construct new implementations of structures and/or stator assemblies.

A first general aspect of the invention is a sealless pump or turbine module with an integrated motor or generator. The module includes an inlet located at the proximal end of the module, the inlet being at the central axis of the module, an outlet located at the distal end of the module, the outlet being at the central axis of the module, and surrounding the module. a module housing, a rotor suspended within the module housing, and a motor within the module housing configured to drive rotation of the rotor, or a generator within the module housing configured to be driven by rotation of the rotor. including.

The motor or generator includes a stator within a sealed stator housing, the stator having at least one electromagnet facing the rotor, the stator housing being removable relative to the module housing; an axially, radially, and rotationally secured stator and an electrical port formed in the stator housing to form a seal with the module housing when the stator housing is secured to the module housing; an electrical port configured to provide a sealed passageway through which an electrical conductor can be directed for interconnection between the at least one electromagnet and a device external to the module housing; a plurality of magnetic devices assembled to the body, the magnetic devices being axially fixed and removably restrained for rotational cooperation with the rotor, the magnetic devices being configured to rotate the at least one magnetic device by the magnetic structure as the rotor rotates; The magnetic device has a magnetic device configured to pass near the electromagnet and a flow path symmetrically distributed around the stator housing.

Additionally, the module is configured to direct the flow of working fluid from the inlet through the flow path to the outlet such that the working fluid is distributed symmetrically around the stator housing as it flows through the stator in the flow path. be done.

In embodiments, the flow path is an annular flow path surrounding the stator housing.

In any of the above embodiments, the flow path may include a plurality of flow paths symmetrically arranged around the stator housing.

In any of the above embodiments, the rotor can be suspended by a rotating shaft, the rotor can be fixed to the shaft, or the rotor can be suspended by a fixed shaft, and the rotor can be , can be configured to rotate about a shaft.

In embodiments where the rotor is suspended by a fixed shaft and the rotor is configured to rotate about the shaft, the rotor can be supported on the fixed shaft by a pair of bearings, one bearing supporting the rotor. Alternatively, the rotor can be supported axially and radially on a fixed shaft by a single one-way thrust bearing. In any of these embodiments, the rotor may be supported on a fixed shaft by at least one bearing that is lubricated by a process fluid. In any of these embodiments, the fixed shaft may be fixed to at least one of the stator housing and the module housing by means of a threaded attachment piece.

In any of the above embodiments, the magnetic device may be a permanent magnet or a squirrel cage coil.

In any of the above embodiments, the flow path may span at least 50% or more of the surface of the stator housing such that at least 90% of the working fluid flowing through the module from inlet to outlet is in direct thermal contact with the stator housing. It is made to flow in a state of

In any of the above embodiments, the module may be configured to require that all working fluid flowing from the inlet to the outlet flow through the flow path.

Any of the above embodiments may further include insulation sandwiched between the flow path and the stator housing, and a cooling fluid path formed between the insulation and the stator housing, the cooling fluid path being , is configured to be in thermal communication with the stator housing and to enable heat exchange between the stator housing and the cooling fluid flowing through the cooling fluid path.

In any of the above embodiments, the stator may be configured to rotate independently of the rotor and in a direction opposite to the direction of rotation of the rotor.

Any of the above embodiments may further include a diffuser that cooperates with the rotor but is capable of rotating independently of the rotor because it is driven by a separate diffuser motor.

In any of the above embodiments, the stator electromagnets may be oriented toward the radial circumference of the rotor, and the magnetic devices may be fixed near the radial circumference of the rotor. Alternatively, the stator electromagnets can face towards the side of the rotor and the magnetic device can be fixed to the side of the rotor or to a disk coaxial and proximal to the side of the rotor.

And in any of the above embodiments, the magnet structure can be sealed, thereby preventing working fluid from reaching the magnetic device.

A second general aspect of the invention is a multi-stage device that includes a plurality of interconnected modules. Each module has an inlet located at the proximal end of the module, the inlet being at the central axis of the module, an outlet located at the distal end of the module, the outlet being at the central axis of the module; and a rotor suspended within the module housing.

Each module further includes a motor within the module housing configured to drive rotation of the rotor or a generator within the module housing configured to be driven by rotation of the rotor. The motor or generator includes a stator within a sealed stator housing, the stator having at least one electromagnet directed toward the rotor, the stator housing being removably axially oriented with respect to the module housing. an electrical port formed in the stator housing and configured to form a seal with the module housing when the stator housing is secured to the module housing; providing a sealed passageway through which an electrical conductor can be interconnected between the at least one electromagnet and a device external to the module housing, axially fixed and rotatably cooperating with the rotor; a plurality of magnetic devices assembled to a magnetic structure removably restrained for a rotor, the magnetic devices being configured to pass close to the at least one electromagnet by the magnetic structure as the rotor rotates; and flow passages that are symmetrically distributed around the stator housing.

Additionally, each module is configured to direct the flow of working fluid from the inlet through the flow path to the outlet such that the working fluid is distributed symmetrically around the stator housing as it flows past the stator within the flow path. has been done.

In embodiments of this general aspect, at least two of the module's motors or generators may be independently controlled to rotate corresponding rotors at separate speeds. And in some of these embodiments, the two independently controlled motors or generators are controlled by separate variable frequency drives.

In any of the above embodiments of this general aspect, the modules may be configured such that the entire device can continue to function as a pump or turbine even if at least one of the modules included in the device fails.

Any of the above embodiments of this general aspect may further include control electronics that provide shared support for at least two modules.

In any of the above embodiments of this general aspect, the plurality of interconnected modules may include at least three interconnected modules.

And in any of the above embodiments of this general aspect, the magnet structure of each module can be sealed, thereby preventing working fluid from reaching the magnetic device.

The features and advantages described herein are not exhaustive, and many additional features and advantages will be apparent to those skilled in the art, particularly in view of the drawings, specification, and claims. Furthermore, it is noted that the language used herein has been chosen primarily for readability and descriptive purposes and is not intended to limit the scope of the inventive subject matter.

FIG. 1 is a cross-sectional view drawn to scale of a prior art two-stage integral motor pump cooled with a dedicated cooling flow.

FIG. 2A is a simplified cross-sectional view of a single stage module of the present invention having a radial motor design.

FIG. 2B is a to-scale side cross-sectional view of a two-stage embodiment of the invention having an axial motor design.

FIG. 2C is a side exploded cross-sectional view drawn to scale of one of the rotor assemblies of substantially the same embodiment as FIG. 2B.

FIG. 2D is an exploded, to-scale perspective view of the rotor assembly of FIG. 2C, drawn to scale.

FIG. 2E is an exploded perspective cross-sectional view drawn to scale of the rotor assembly of FIG. 2C.

FIG. 2F is a front perspective view, drawn to scale, of one of the stator assemblies of an embodiment substantially similar to the embodiment of FIG. 2B.

FIG. 2G is a side perspective view, drawn to scale, of the stator assembly of FIG. 2F.

FIG. 2H is a simplified cross-sectional view of an embodiment including an annular flow path through an annular space.

FIG. 2I is a cross-sectional view substantially the same as FIG. 2H, but including an additional concentric layer of insulation and concentric cooling annular passages.

FIG. 2J is a simplified cross-sectional view of an embodiment that includes a plurality of flow passages evenly distributed around and insulated from the coil housing of a motor or generator.

FIG. 3 is a to-scale cross-sectional view of an embodiment substantially similar to FIG. 2, but including separate cooling channels (cooling channels not drawn to scale).

FIG. 4 is a cross-sectional view, drawn to scale, of an embodiment similar to FIG. 2 but including guide vanes in the process flow path.

FIG. 5 is a perspective view, drawn to scale, of the outer housing of the pump of FIGS. 2C-2G.

FIG. 6A is a to-scale side cross-sectional view of a two-stage embodiment of the invention having a modular motor design.

FIG. 6B is a side cross-sectional view drawn to scale of one of the rotor and magnet structure assemblies of the embodiment of FIG. 6A.

FIG. 6C is an exploded side cross-sectional view drawn to scale of the rotor and magnet structure of FIG. 6B.

FIG. 6D is an exploded, to-scale side and front perspective view of the rotor and magnet structure of FIG. 6C.

FIG. 6E is an exploded perspective view, drawn to scale, from the side and back of the rotor and magnet structure of FIG. 6D.

FIG. 6F is an exploded, to-scale perspective side and front view of one of the stator assemblies of FIG. 6A with the rear plate removed;

FIG. 6G is an exploded, to-scale, side and front perspective view of the stator assembly of FIG. 6F, with the back plate welded in place;

FIG. 6H is an exploded, to-scale, side and rear perspective view of the stator assembly with welded back plate of FIG. 6G.

FIG. 6I is a perspective view, drawn to scale, of the outer housing of the pump of FIGS. 6A-6H.

Figure 7A shows a four-module pump that is of a different design than the pumps of Figures 6A-6H, but incorporates the same modular stator and magnet structure design included in the pump modules of Figures 6A-6H. FIG. 2 is a perspective view drawn to scale.

FIG. 7B is a cross-sectional, to-scale side view of a single module of the pump of FIG. 7A, viewed from the to-scale side.

FIG. 7C is an exploded, to-scale cross-sectional view of the module of FIG. 7B from a to-scale side view.

The present invention is a "sealless" motor pump or sealless generator turbine configured as a module with a flow "concentric" design. By way of example, a pump embodiment 200 of the present invention is shown in FIG. 2A. As can be seen, the housing 204 of the motor coil 212, ie the stator housing 204, is surrounded by the housing 218 of the module, forming an annular space 202 therebetween. According to the invention, the working fluid is distributed along the annular space 202 between multiple channels or through a single annular channel. The distribution of the working fluid into the annular space 202 may be symmetrical with respect to the stator housing 204. In the embodiment of FIG. 2A, annular space 202 functions as an annular flow path 202 through which working fluid flows from inlet 222 to outlet 224. In the embodiment of FIG.

In the embodiment of FIG. 2A, annular channel 202 is in direct thermal contact with housing 204 of motor coil 212. This configuration is suitable for applications where the working fluid is relatively cold. In the illustrated embodiment, the working fluid is directed by the rotor 206 through the annular passage 202 along the outside of the module's motor coil housing 204 such that the motor coil 212 is It is directly cooled and does not require a separate dedicated cooling fluid.

In embodiments, the concentric design of the present invention is realized as a self-contained, extremely compact module that can be used alone, as shown in Figure 2A, or as a multi-stage pump, as shown in Figure 2B. Or multiple identical modules can be used in combination to form a turbine. This modular approach allows the design to be expanded to any number of stages without adding additional complexity or complexity to the design, operation, and maintenance of the device. In particular, the large number of stages does not create any problems with respect to shaft size, shaft deflection, rotational dynamics, bearing loads, motor alignment, or stage alignment.

More particularly, FIG. 2B shows a two-stage pump embodiment 220 in which the central axis of the motor 212 of each stage 200 is substantially collinear with the stationary shaft 208 about which the rotor 206 rotates. , whereby process fluid coming from the rotor 206 flows axially outside the stator housing 204 through an annular passageway 202 formed between the stator housing 204 and the pump housing 218 of each stage 200 . Although only two stages 200 are shown in FIG. 2B for illustrative purposes, it will be appreciated that the embodiment can be extended to any number of stages of pump 200.

In some multi-stage embodiments, the rotors 206 of each stage 200 are driven independently so that the rotor speed of each stage 200 can be controlled separately. For example, a separate variable frequency drive (“VFD”) 216 may be dedicated to controlling each stage 200 of the pump.

In the embodiment of FIG. 2B, in each stage 200 of the pump 220, a plurality of permanent magnets 210 are mounted directly behind the rotor 206 so that as the rotor 206 rotates, it closes the electromagnetic coil 212 of an adjacent stator 212. be allowed to pass. Other embodiments of the rotor 206 include induction motors that utilize non-permanent magnets 210, such as "squirrel cage" rotor coils, in which current is induced by stator electromagnets 212 during pump or turbine operation. This transfers torque directly from the electromagnetic motor coil 212 to the rotor 206, or electromagnetic energy is transferred from the rotor to the generator coil without utilizing shaft rotation. In embodiments, the motor coils 212 are sealed from the working fluid using a static sealing method (not shown), thereby eliminating the need for dynamic mechanical seals that would otherwise result therefrom. Avoid potential alignment, leakage, and/or maintenance problems.

In the embodiment of FIG. 2B, axial and radial positioning of each stage of rotor 206 is provided by product lubricated bearings 214. By using individual bearings 214 for each rotor stage 200, the bearings 214 of each stage 200 can be designed to handle only the loads from that stage, and the bearings can be overloaded from the combined stage loads in a multi-stage configuration 220. The risk of overloading is completely eliminated. Using a working fluid as a lubricant for the bearings 214 in embodiments eliminates the need for an external oil lubrication system, greatly simplifying overall pump design and maintenance.

2C-2E are an exploded side sectional view, an exploded perspective view, and an exploded perspective sectional view, respectively, of one of the rotor assemblies of substantially the same embodiment as FIG. 2B. In the illustrated embodiment, the magnet 210 is included in a magnet structure 252 that further includes a magnet "base" 236 and a magnet structure cover plate 238. The assembled magnet structure 252 is installed in an annular cavity 240 provided in the rotor 206.

2F and 2G are front and side perspective views, respectively, of one of the stator assemblies of the embodiment of FIGS. 2B-2E. Stator coils (not shown) are wrapped in foam 242 within coil cavity 250 and covered with stator cover plate 244 . Electrical leads from the coil 212 are directed through an electrical port 246 that extends from inside the coil cavity 250 through the stator aft flange sealed to the pump or turbine housing 200. In embodiments, stator coil 212 is potted within coil cavity 250.

In some embodiments, such as FIG. 2A, each stage of rotor 206 is fixed to a rotating shaft 208. In other embodiments, such as FIG. 2B, the shaft 208 of each stage is inserted through the hub of the rotor 206 and secured to the coil housing 204 of the motor or generator, and the rotor 206 is mounted around the shaft 208, e.g. Rotates on 214. This approach makes it easy to assemble and maintain without special tools. In similar embodiments, the shaft 208 is threaded or otherwise supported by a pump or turbine module housing 218 or by any combination of a pump or pump module housing 218 and a motor or generator stator housing 204. be done.

Certain embodiments include a module 200 in which the rotor and stator configuration is reversed, allowing both rotor 206 and stator 212 to rotate independently in opposite directions. Some embodiments include multiple rotors 206 that are fixed to a common fixed or rotating shaft 208 and combined with a stator and/or individually rotating diffusers. In some of these embodiments, the diffuser is implemented in a manner similar to the disclosure of U.S. patent application Ser. No. 15/101,460, which is incorporated herein by reference in its entirety for all purposes. .

In still other embodiments, there is no shaft 208, and instead the wear ring gap in front of each rotor 206 acts as the primary radial and axial bearing. This either transfers torque directly from the motor's electromagnetic stator coil 212 to the rotor, or transfers electromagnetic energy from the rotor 206 to the generator's coil 212, without using a rotating shaft.

FIG. 2H is a simplified cross-sectional view of an embodiment having substantially the same annular flow path as FIG. 2A, with the cross-section taken through the pump motor coil 212 perpendicular to the main axis of the motor.

The embodiment of FIGS. 2A-2H is suitable when using a relatively cold working fluid, and the annular flow path 202 places the working fluid in direct thermal contact with the coil housing 212 of the motor or generator, thereby Cool motor or generator coils. 2A-2H, more than 80% of the working fluid is in thermal contact with the motor or generator coil housing 212 and at least 20% of the motor or generator coil housing 212 is in thermal contact with the annular channel 202. There is. In various embodiments, more than 90% of the working fluid is in thermal contact with the motor or generator coil housing 204 and at least 50% of the motor or generator coil housing surface 204 is in thermal contact with the annular flow path 202. There is.

Referring to FIG. 2I, in some embodiments where high temperature working fluids are anticipated, the design of FIG. Modified by the inclusion of insulation 228. In some of these embodiments, a concentric cooling annular passage 234 is further provided between the insulation 228 and the coil housing 204 through which a cooling fluid, such as water or cooling oil, flows from the inlet 230 to the outlet 232. be able to.

Referring to FIG. 2J, in other embodiments, the working fluid is distributed between a plurality of substantially identical flow passages 226 symmetrically disposed within the annular space 202 around the circumference of the stator housing 204. . In the embodiment of FIG. 2J, the flow path 226 is formed by the module housing wall 218. The embodiment of FIG. 2J, like FIG. 2I, further includes concentric annular layers of insulation 228 and concentric cooling annular passages 234.

Referring to FIG. 3, in embodiments, a small amount of working fluid is detoured through a separate cooling path 300 where it is cooled and then passed through a concentric annular cooling passage 234 in thermal contact with the stator housing 204. The current flows and cools the motor coil 212. In similar embodiments, a separate cooling fluid, such as water or cooling oil, flows through cooling path 300 without bypassing the working fluid.

Fluid cooling of the motor or generator coils 212 in various embodiments allows the system to operate with higher temperature working oil, allowing the system to operate at higher temperatures across the pump or turbine without increasing the temperature of the working fluid. It also becomes possible to achieve performance limits and higher power densities.

Referring to FIG. 4, embodiments include guide vanes 400 within the annular channel 202 if the channel is annular, or anywhere else within the channel. In the illustrated embodiment, the guide vanes 400 control the flow of process fluid in sections of concentric channels at the ends of the motor or generator coils 212, with the channels radially toward the central axis of the module. Turn inward. The guide vanes 400 divide the flow path into multiple distinct but symmetrical paths until the flow reaches the central axis and exits axially through the outlet 224 to enter the next stage 200. In embodiments, guide vanes 400 direct process fluid within the flow path in close proximity to motor or generator stator housing 204 .

Guide vane 400 can also be a casing wall that can be used to route power cables from a sealed motor or generator 212 through fluid passageway 202 and from pump casing 218 to variable frequency controller 216. In embodiments, the guide vanes 400 provide additional convective surface area for cooling the motor or generator coils 212 and/or provide space for integral cooling passages 300 that connect to an external cooling fluid source. It also acts as a fin.

FIG. 5 is a perspective view of the external appearance of the pump of FIGS. 2C to 2G.

Referring to FIG. 6A, in various embodiments 610, the motor or generator is modular in design, such that a particular motor or generator design can be incorporated into multiple different pump or turbine designs. In the example of FIG. 6, the plurality of magnetic devices 210 that cooperate with the rotor of the motor are incorporated into a removable magnet structure 600 that can be secured to and removed from the rotor 206 of the pump 200. Attaching the magnet structure 600 to the rotor can be by any means known in the prior art that can constrain the magnet structure 600 both axially and rotationally relative to the rotor. Some embodiments include a component that threads the magnet structure onto the rotor, which constrains the magnet structure both axially and rotationally. In the embodiment of FIG. 6, magnet structure 600 is attached to rotor 206 by bolts 602, which constrain magnet structure 600 both axially and rotationally relative to rotor 206.

The embodiment of FIG. 6A further includes an electrical port 608 (see FIG. 6H) that provides a sealed conduit from the coil cavity 250 in the stator housing 204 containing the stator coil 212 to the module housing 218 . Extending through aft flange 248 , thereby providing a passageway for electrical leads 606 and/or control lines to extend between stator coil 212 and the external environment of pump 200 . It can be seen that the module housing 218 has a flange 248 that is bolted and sealed at the rear end. Flange 248 has a female socket 604 into which an electrical port 608 is inserted, with which electrical port 608 forms an O-ring seal.

In embodiments, the motor or turbine magnet structure 600 and/or stator portion 204 containing the stator coils are modular and fully sealed so that they are mechanically connected to the pump or turbine housing 200 in close proximity to each other. You just need to put it on. In various embodiments, the sealed modular magnet structures 600 and/or sealed modular stator assemblies 204 of the present invention can be implemented in different combinations, each time a new pump or turbine module is designed. There is no need to construct new implementations of the magnet structure 600 and/or stator assembly 204 at any time.

FIG. 6B is an enlarged cross-sectional view of one of the rotor 206 and magnet structures 600 of FIG. 6A shown in an assembled state. FIG. 6C is a cross-sectional exploded view of the rotor 206 and magnet structure 600 of FIG. 6B. 6D and 6E are front and rear exploded perspective views of the rotor 206 and magnet structure 600 of FIG. 6B. FIG. 6F is an enlarged front exploded perspective view of one of the stator assemblies of FIG. 6A, shown in relation to the rear flange 248 of the pump housing. It can be seen that the guide vane 400 located in the process fluid outlet flow path is secured to the rear flange 248 and the module rear plate 244 has been removed to reveal the interior. FIG. 6G is the same as FIG. 6F except that rear plate 244 is welded in place, thereby completing the sealed stator module. FIG. 6H is an enlarged exploded perspective view from the rear of the stator assembly of FIG. 6G. Electrical ports 608, which serve as conduits for stator coil leads 606, are clearly visible in the figure. FIG. 6I is a perspective view of the pump 610 of FIG. 6A, fully assembled.

FIG. 7A is a perspective view of a four module pump design 700 that differs significantly from the pumps of FIGS. 6A-6H. 7B is a cross-sectional view of a single module 708 of the pump of FIG. 7A, and FIG. 7C is an exploded cross-sectional view of the module 708 of FIG. 7B. It can be seen that the design shown includes the diffuser 702, and that the rear flange 248, pump rotor 206, stator housing 204, and pump housing 218 are all different from the design shown in FIGS. 6A-6H. This means that they are quite different. Nevertheless, the pump 700 of FIGS. 7A-7C incorporates essentially the same modular motor components as included in FIGS. 6A-6H. The only minor difference is that in the illustrated embodiment, a snap ring 704 is used to axially constrain the magnet structure 600 and a pin 706 is used to rotationally constrain the magnet structure 600. That is the point. However, it is obvious that bolts can be used to constrain the magnet structure as in FIGS. 6A-6H with only slight design changes.

Although only two pump modules 200 are shown in FIGS. 2B, 4, 6A, and 6H, pump 700 in FIG. 7 includes five modules. In general, it will be readily appreciated that in embodiments, any number of the disclosed pump or turbine stages 200 may be combined in series without adding any additional complexity or complexity to the pump or turbine 200 design, operation, and maintenance. . In particular, increasing the number of stages according to the disclosed design does not create any problems with shaft size, shaft deflection, rotor mechanics, bearing loads, motor alignment, or the alignment of stages 200 with each other.

Certain embodiments include at least some drive electronics that are shared between two or more stages. For example, in some embodiments, AC power is converted to DC power by a common set of heavy-duty electronics and distributed to individual pump or turbine stages as needed. Other embodiments include multiple variable frequency drives (“VFDs”) 216, and in some of these embodiments, the motor or generator coil 212 of each stage 200 of the pump or turbine has a dedicated VFD 216 or other independently controlled by the controller. One important advantage of some of these embodiments is that the first stage runs slower than the rest of the pump to accommodate low net suction head ("NPSH") and off-peak conditions. It is possible. In some applications, varying the speed of only the last stage can be a useful technique to precisely control output pressure and/or flow.

Providing individual VFD drives 216 for each stage 200 can also serve as fail-safe redundancy, so that if one stage fails, the rest will continue to operate and the pump will continue to function. . Continuing function after a pump stage fails may be at lower head and flow rates, or the speed of the remaining stages may be increased to compensate for the loss of head and flow rate of the failed stage. This approach creates a failure scenario in which the pump continues to operate at potentially lower head and flow rates until the operator has time to safely shut down the system after noticing a stage failure. In contrast, when one stage of a conventional pump or turbine fails, the entire pump or turbine typically fails, resulting in a complete loss of performance and a sudden and uncontrollable shutdown of the system.

In the embodiment of FIG. 2A, the motor is a radial motor that includes permanent magnets mounted around the circumference of the rotor, but other embodiments illustrated include permanent magnets 210 located behind the back of the rotor 206. The rotor 206 includes a disc or "pancake" style rotor 206 incorporating a rotor. Other embodiments use induction motors. Some embodiments include a variable speed drive that allows the synchronous operating speed of pump stage 200 to increase above 3600 rpm.

In the illustrated embodiment, pump stage 200 is a centrifugal design with a radial flow rotor 206. Some of these embodiments include rotors with specific speeds up to about 2000 US units, in some embodiments up to 4000 US units, and even 5000 US units. Other embodiments include a pump stage 200 that is a radial flux rotor design.

The illustrated embodiment uses a combination of radial and unidirectional thrust bearings 214 instead of separate axial and radial bearings. The illustrated embodiment includes a stationary shaft 208 inserted through the hub of the rotor 206 and screwed to the pump stage housing 218, facilitating easy assembly and maintenance without special tools. . The use of sensorless motors with appropriate VFD drives 216 also reduces instrumentation requirements for each stage 200 of the illustrated embodiment.

Certain embodiments of the invention include a modular stage 200 in which the rotor and stator configuration is reversed, such that both the rotor and stator can rotate in opposite directions independently of each other. And, some embodiments include separately rotating stators and/or diffusers, eg, using separate motors to drive the rotor and diffuser. In some of these embodiments, the diffuser is implemented in a manner similar to the disclosure of US patent application Ser. No. 15/101,460.

As is known in the prior art, turbopumps and turboturbines are often very similar in physical design, so the difference between pumps and turbines may be primarily a matter of use rather than construction. Thus, although the illustrated embodiment is a pump, features of the invention discussed herein with respect to turbines or pumps should be understood to refer equally to both, unless the text clearly indicates otherwise.

The above description of embodiments of the invention has been presented for purposes of illustration and description. Each page of this application and its entire contents, regardless of their character, identification, numbering, form or arrangement within the specification, is considered to be an integral part of this specification for all purposes. It will be done. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure.

Although this specification is shown in a limited number of forms, the scope of the invention is not limited to only these forms, and is susceptible to various changes and modifications without departing from the spirit thereof. It is possible. The disclosure presented herein does not explicitly disclose all possible combinations of features that fall within the scope of the invention. The features disclosed herein with respect to the various embodiments can generally be substituted and combined in any consistent combination without departing from the scope of the invention. In particular, the limitations set forth in the following dependent claims may apply to the corresponding independent claims in any number and in any order, unless the dependent claims are logically incompatible with each other and do not depart from the scope of this disclosure. Can be combined with terms.

Claims (26)

A sealless pump or turbine module having an integrated motor or generator, the module comprising:
an inlet located at the proximal end of the module, the inlet being in the central axis of the module;
an outlet located at the distal end of the module, the outlet being in the central axis of the module;
a module housing surrounding the module , the module housing terminating proximate the outlet by a rear flange of the module housing;
a rotor suspended within the module housing;
a motor in the module housing configured to drive rotation of the rotor, or a generator in the module housing configured to be driven by rotation of the rotor; The machine is
a stator within a sealed stator housing, the stator having at least one electromagnet directed toward the rotor; , rotatably fixed ,
a plurality of magnetic devices assembled to a magnetic structure that is axially fixed and removably constrained for rotational cooperation with the rotor, the magnetic devices being assembled to the magnetic structure by the magnetic structure as the rotor rotates; a magnetic device configured to pass near at least one electromagnet;
flow passages symmetrically distributed around the stator housing; configured to direct a flow of working fluid from the inlet through the flow path to the outlet ;
a plurality of guide vanes in the flow path, each of which is fixed to the rear flange and separates the flow path until the flow reaches the central axis and exits axially through the outlet; a plurality of guide vanes configured to divide into a plurality of symmetrical paths;
a female socket extending through one of the plurality of guide vanes and the aft flange;
an electrical port extending from the stator housing and configured to be inserted into the female socket to provide a sealed conduit through which conductive wires may be directed from the stator coil to devices external to the module housing; A module comprising : 2. The module of claim 1, wherein the flow path is an annular flow path surrounding the stator housing. 2. The module of claim 1, wherein the flow path includes a plurality of flow paths symmetrically arranged around the stator housing. 4. A module according to any one of claims 1 to 3, wherein the rotor is suspended by a rotating shaft, and the rotor is fixed to the shaft. 4. A module according to any one of claims 1 to 3, wherein the rotor is suspended by a fixed shaft and the rotor is configured to rotate about the shaft. 6. The module of claim 5, wherein the rotor is supported on the stationary shaft by a pair of bearings, one bearing holding the rotor in an axial position and the other bearing holding the rotor in an axial position. A module that supports radially. 7. A module according to claim 5 or claim 6, wherein the rotor is supported axially and radially on the fixed shaft by a single unidirectional thrust bearing. 8. A module according to any one of claims 5 to 7, wherein the rotor is supported on the stationary shaft by at least one bearing that is lubricated by a process fluid. 9. A module according to any one of claims 5 to 8, wherein the fixed shaft is fixed to at least one of the stator housing and the module housing by a threaded mounting part. 10. A module according to any one of claims 1 to 9, wherein the magnetic device is a permanent magnet. 10. A module according to any one of claims 1 to 9, wherein the magnetic device is a squirrel cage coil. 12. A module according to any one of claims 1 to 11, wherein the flow path spans at least 50% or more of the surface of the stator housing and the actuation flow through the module from the inlet to the outlet. A module wherein at least 90% of the fluid is flowed in direct thermal contact with the stator housing. 13. A module according to any one of claims 1 to 12, wherein the module is configured such that all of the working fluid flowing from the inlet to the outlet is channeled through the flow path. . 14. A module according to any one of claims 1 to 13, comprising:
a heat insulating material sandwiched between the flow path and the stator housing;
further comprising a cooling fluid path formed between the insulating material and the stator housing, the cooling fluid path being in thermal communication with the stator housing and communicating with the cooling fluid flowing through the stator housing and the cooling fluid path. A module configured to allow heat exchange between the modules. 15. The module according to any one of claims 1 to 14, wherein the stator is configured to rotate independently of the rotor in a direction opposite to the rotational direction of the rotor. . 16. A module according to any one of claims 1 to 15, further comprising a diffuser cooperating with the rotor but rotatable independently of the rotor to be driven by a separate diffuser motor. module. 17. A module according to any one of claims 1 to 16, wherein the electromagnet of the stator is oriented toward the radial periphery of the rotor, and the magnetic device is oriented near the radial periphery of the rotor. Fixed to the module. 17. A module according to any one of claims 1 to 16, wherein the electromagnet of the stator is directed towards the side of the rotor, and the magnetic device is at or coaxial with the side of the rotor. module, which is fixed to the proximal disc at. 19. A module according to any one of claims 1 to 18, wherein the magnet structure is sealed, thereby excluding the working fluid from reaching the magnetic device. A multi-stage device comprising a plurality of interconnected modules, each said module being a module according to claim 1. 21. The apparatus of claim 20, wherein at least two of the motors or generators of the module are independently controlled and capable of rotating the corresponding rotors at separate speeds. 22. The apparatus of claim 21, wherein the two independently controlled motors or generators are controlled by separate variable frequency drives. 23. The device according to any one of claims 20 to 22, wherein the module is such that even if at least one of the modules included in the device fails, the entire device continues to function as a pump or a turbine. A device configured to allow 24. Apparatus according to any one of claims 20 to 23, further comprising control electronics providing shared support for at least two said modules. 25. The apparatus of any one of claims 20 to 24, wherein the plurality of interconnected modules comprises at least three interconnected modules. 26. Apparatus according to any one of claims 20 to 25, wherein the magnetic structure of each of the modules is sealed, thereby excluding the working fluid from reaching the magnetic device. Device.

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